#### Use and Misuse of Chi-square

Before using any adaptations of chi-square statistic, please spend a minute or two to ponder whether your strategy with chi-square belongs one of these categories.

**1**. Lack of independence among the single events or measures

**2**. Small theoretical frequencies

**3**. Neglect of frequencies of non-occurrence

**4**. Failure to equalize \sum O_i (the sum of the observed frequencies) and \sum M_i (the sum of the theoretical frequencies)

**5**. Indeterminate theoretical frequencies

**6**. Incorrect or questionable categorizing

**7**. Use of non-frequency data

**8**. Incorrect determination of the number of degrees of freedom

**9**. Incorrect computations (including a failure to weight by N when proportions instead of frequencies are used in the calculations)

From “**Chapter 10: On the Use and Misuse of Chi-square**” by K.L.Delucchi in *A Handbook for Data Analysis in the Behavioral Sciences* (1993). Delucchi acknowledged these nine principle sources of error to Lewis and Burke (1949), entitled “The Use and Misuse of the Chi-square” published in *Psychological Bulletin.* Continue reading ‘Use and Misuse of Chi-square’ »